On the first day of medical school we were told that half of what we would be taught would be proven false. We just didn't know which half. If people knew that they might take medical gospel with a grain of salt. But we all have a need to believe in experts, especially when we're sick. Trying to swim through the medical literature to find out what's what is difficult enough for the highly trained medical researcher. And sometimes things are only half wrong.
Statins (cholesterol lowering drugs) are the most widely prescribed medications in the US, taken by over 40 million people. The story of how this group of medications climbed to such prominence is a perfect example of a therapeutic intervention based on false assumptions that has life-saving effects.
Coronary heart disease (clogging of the arteries that feed the heart causing heart attacks) is the principal cause of death in the developed world. Atherosclerosis (the accumulation of plaque on the walls of the coronaries) is the primary disorder in coronary heart disease. Researchers found an association between elevated blood LDL cholesterol and increased atherosclerotic disease. Statins were observed to lower this bad cholesterol and reduce coronary heart disease. Eureka! Case closed.
But there is no apparent association between coronary events and the level of LDL reduction. In fact many patients who achieve recommended LDL cholesterol goals still develop the complications of atherosclerosis. So what gives?
It so happens that statins do many things in addition to lowering cholesterol. They reduce inflammatory responses and our tendency to form clots. The atherosclerotic plaques that already exist in our coronaries are stabilized by statins so they don't shed particles that plug up the heart's blood vessels. And the pathological process that occurs in the tissue that lines our coronaries (endothelium) and leads to plaque formation is markedly improved by statins. Inflammation, clotting, unstable plaque, and disease of the endothelium are the primary causes of coronary heart disease, not cholesterol.
And that's not all. A recent study looking at statin users after 11 years suggests that they had a lower death rate from all causes. This increased survival amongst statin users was mainly attributed to a reduction in deaths from infection and respiratory illness, not cardiovascular deaths.
Lipitor's legacy? We still don't know the half of it.